The present invention relates to a pneumatic-tube conveyor system. More particularly this invention concerns a terminal for such a system.
A standard pneumatic-tube conveyor comprises a tube along which carriers are moved by pneumatic pressure. Along the tube there are various stations or terminals where a carrier moving along the tube can be diverted and taken out of the system and where a carrier can be introduced into the system. The systems are often set up as endless loops such that a carrier will eventually pass every terminal in the system, no matter where it is introduced. Such systems are typically used for moving small objects and papers over substantial distances, for instance in a large retail or warehouse operation. Such a system is described in German patent document 3,801,558 of J. Walther and 3,709,319 of H. Storzer.
In the most sophisticated systems each carrier has a unique identity carried in a radio-frequency transponder that can be read as the carrier moves along the tube, and simpler systems use bar codes to the same effect. Each terminal furthermore has its own station code and all the stations are connected to a computer system so that when a carrier is filled at one station it is only introduced into the tube system and sent on its way once the carrier""s identity has been passed to the station to receive it so that it will know to divert the carrier as it passes.
Such a conveyor is particularly effective in a hospital or the like for delivering drug orders from a centralized pharmacy to the wards. The drugs are loaded at a secure location by the pharmacy into the conveyor and the terminal they are addressed to diverts them when they pass and holds them for dispensing in the ward.
The main problem with this system is that anyone who has access to the remote terminal can get at the drugs delivered to it. Typically the standard passage terminal just dumps the carriers it receives in a basket accessible to anyone at the location.
Thus Austrian patent 395,310 describes a system where a second rotor is provided so that the intercepted carrier is held in the terminal until it is opened and retrieved by someone authorized to open the terminal. The problem with this arrangement is that it takes the terminal out of service while it is holding a carrier, that is it cannot be used for dispatching or intercepting a carrier and in fact the terminal is blocked while it is holding a carrier for retrieval by an authorized user. This makes the system unusable in a large-scale operation with substantial carrier traffic, as the system is largely down until a carrier is retrieved from a locked terminal.
It is therefore an object of the present invention to provide an improved terminal for a pneumatic-tube conveyor.
Another object is the provision of such an improved terminal for a pneumatic-tube conveyor which overcomes the above-given disadvantages, that is which will not allow unauthorized persons access to received carriers.
A terminal for connection between sections of a pneumatic tube for passing and intercepting carriers passing along the tube has according to the invention upper and lower end walls spaced apart along an axis and having respective upper and lower ports respectively connected to the tube sections. The lower end wall also has angularly offset from the respective tube section an outlet port. A rotor rotatable about the axis between the end walls between a pass-through position and an intercept position has a pass-through tube aligned between the tube sections only in the pass-through position and an intercept tube aligned between the tube sections only in the intercept position and aligned with the outlet port in the pass-through position. The intercept tube is adapted to brake and stop a carrier. A closing plate between the rotor and the lower wall has an axially throughgoing aperture and is displaceable between a closed position blocking the outlet port and with the aperture over and permitting movement through the lower port and an open position with the aperture over and permitting passage through both the lower and outlet ports. A user-specific lock can displace the closing plate into the open position.
Thus with this arrangement the terminal remains open and can still pass carriers even when it is securely holding a carrier for pickup. According to the invention a second rotor separate from the first-mentioned rotor is rotatable about the axis between the end walls between a loading position and a dispatch position. The second rotor has a loading tube with a lateral loading opening and aligned with the tube sections in the dispatch position and not aligned with the tube sections in the loading position. This second rotor can therefore be used to send back or dispatch a carrier even when the terminal is in secure mode holding a carrier for pickup, in which case of course the first rotor is movable into a position with both its tubes out of alignment with the upper and lower tube sections.
The plate is rotatable about the axis between the closed and open positions. In this case its aperture is angularly elongated. It is also possible for the closing plate to be slidable generally radially of the axis between the closed and open positions.